An interior rearview mirror assembly for use in a vehicle includes a mirror stay assembly and an interior mirror. The mirror stay assembly includes a rigid mirror stay for attachment to an interior portion of the vehicle, a support member for the interior mirror, and at least one electronic accessory. The interior mirror has a reflective mirror element housed in a mirror housing and also includes at least one electronic accessory. The electronic accessory of the mirror stay preferably shares components with the electronic accessory of the interior mirror, and/or provides circuitry for the electronic accessory of the interior mirror. The electronic accessories can be an information display, light, antenna, video device, microphone, photosensor, detector, computer, printer, circuitry of various types, or other items.